1. Field of the Invention
This invention relates to a time-and-distance measurement apparatus and, more particularly, to an instrument which facilitates calculation of the acceleration or deceleration of a motor vehicle involved in a collision.
2. Description of the Related Art
In the science of vehicular accident reconstruction, investigators, scientists, engineers and forensic specialists attempt to recreate, after the fact, the sequence of events immediately preceding an accident to determine the contributing factors to the accident. It is often critically important for the investigator to assess variables such as the effect of the weather on the accident and of pavement conditions, the braking efficiency of the vehicles in question, the acceleration and deceleration of the vehicles involved in the accident, and the performance of the operator of the vehicle in response to the conditions prevailing at the time of the accident.
Influences such as the weather and the condition of the pavement can dramatically affect acceleration, deceleration and braking efficiency of a vehicle. It is important for the investigator to be able to determine these variables as accurately as possible in order to arrive at an informed opinion as to the principal cause of the accident. The accident causation analysis is greatly facilitated if time, distance, velocity, and acceleration calculations can be made directly at the scene of the accident since, in many cases, the ambient conditions immediately subsequent to the accident will be relatively consistent with the conditions immediately prior to and during the accident. However, investigative technology has heretofore consisted of attempts to reconstruct the accident at a time considerably later than the occurrence of the accident. Obviously, it is quite difficult to accurately recreate the ambient conditions prevailing at the time of the accident. Although computer modeling techniques are frequently employed and in recent years have become quite sophisticated, they nevertheless require an estimation of the aforementioned variables.
Thus, there has been a need for an apparatus that facilitates the calculation of acceleration, deceleration, braking efficiency, and like parameters of a motor vehicle involved in an accident immediately following the accident and before the prevailing conditions have changed substantially. Such calculations help to identify mechanical, electrical or hydraulic defects in one or more vehicles involved in an accident, human error in the operation of the vehicles, and thus ultimately the entities liable for costs and losses associated with the accident.